lame

You might describe a limping dog that's lost the use of one of its legs as lame, which means "disabled in a leg or foot."

It's less common than describing injured animals as lame, but you can use this adjective to describe a limping person too. Lame is probably most often used to mean generally weak or pathetic. If your friend threw a Frisbee in your direction and it landed several feet in front of you, you might say, "What a lame throw!"